RESUMEN
Consciousness is one of the most complex aspects of human experience. Studying the mechanisms involved in the transitions among different levels of consciousness remains as one of the greatest challenges in neuroscience. In this study we use a measure of integrated information (ΦAR) to evaluate dynamic changes during consciousness transitions. We applied the measure to intracranial electroencephalography (SEEG) recordings collected from 6 patients that suffer from refractory epilepsy, taking into account inter-ictal, pre-ictal and ictal periods. We analyzed the dynamical evolution of ΦAR in groups of electrode contacts outside the epileptogenic region and compared it with the Consciousness Seizure Scale (CCS). We show that changes on ΦAR are significantly correlated with changes in the reported states of consciousness.
Asunto(s)
Epilepsia , Cristalino , Unionidae , Humanos , Animales , Estado de Conciencia , Teoría de la Información , ConvulsionesRESUMEN
There are many characteristics that differentiate normal moles (nevi) from melanomas. One of them is their boundary irregularity, which can be quantified using Fractal Dimension. In this work, fractal dimension of normal moles and melanoma was computed using the box counting method. These measurements were used to train a linear decoder in order to predict the pathology. The average performance to discriminate normal moles from melanomas reached 85% giving some insights about the power of the fractal dimension as a candidate for automatic detection and diagnosis.
Asunto(s)
Fractales , Melanoma/patología , Neoplasias Cutáneas/patología , Humanos , Melanoma/diagnóstico , Neoplasias Cutáneas/diagnósticoRESUMEN
A new method for spike sorting of tetrode recordings during data acquisition is introduced. For each tetrode channel, putative spikes are detected by means of a threshold, and then convolved with a cascade of wavelet filters. These transformed putative spikes are averaged and this average is used as a matched filter to find portions of signals that are likely to contain a spike. A collection of vectors containing the correlation coefficients between putative spikes and the matched filters is then clustered using K-Means. Centroids of the resulting clusters contain enough information to sort spikes recorded by all tetrode channels simultaneously. On-line sorting is achieved by measuring euclidean distance between putative new spikes and the cluster centroids.